Note: Unless you're documenting a feature that's new to a specific version of Symfony (e.g. Symfony 2.2), all pull requests must be based off of the 2.1 branch, not the master or 2.2 branch.
From the docs README

Hi there!

I've merged in your pull request with minor changes at sha:e3147da. We certainly do like to includeall of the instructions so people can get the examples working, so these are nice additions.

Thanks!